Silver salt diffusion apparatus for carrying out the transfer process



June 23, 1970 w. LIMBERGER 3,516,344

' SILVER SAL FFUSIQN APPARATUS FOR CARRYING THE TRANSFER PROCESS Filed Nov. 22, 1966 7 Shets-Sheet 1 BTTOKMEY'i June 23, 1970 w. LIMBERGER 3,516,344

' SILVER SALT DIFFUSION APPARATUS FOR CARRYING OUT THE TRANSFER PROCESS Filed Nov. 22, 1966 Y 7 Sheets-Sheet 2 Fig. 2'

lnvenfo wane? LI 155x651? DTTO M515 3,516,344 TUS FOR CARRYING ROCESS June 23, 1970 W. LIMBERGER SILVER SALT DIFFUSION APPARA OUT THE TRANSFER P 7 Sheets-Sheet 5 Filed NOV. '22, 1966 lnvenlor: WOLTERV LIMBERGER Mlwrmat {01w DTTORNEY S June 23, 1970 w. LIMBERGER 3,516,344

SILVER SALT DIFFUSION APPARATUS FOR CARRYING I OUT THE TRANSFER PROCESS 7 Sheets-Sheet 4 Filed Nov. 22, 1966 I lnvenlor:

LIHBERGER WRLTER 1 w LIMBERGER 3,516,344 SILVER SALT DIFFUSION APPARATUS FOR CARRYING v OUT THE TRANSFER PROCESS 7 Sheets-Sheet 5 June 23, 1970 Filed Nov. 22, 1966 lnyenfar. 3 WHLTER LI/(BERGER PTTO'RMYs June 23, 1970 SILVER SALT DIFFUSION APPARATUS FOR CARRYING Filed Nov. 22, 1966 w. LIMBERGER 3,516,344

OUT THE TRANSFER PROCESS '7 Sheets-Sheet 6 IIIIIIIIII/IIIIIIII IIIIIIIIIIIIIIIIIIII IIIIIIIITIJIIIIIII s I I l=ml IIHI j I mm 'HHI 1 ||H| 5s v I Ill R Ln 2, I. a I I g 5 Q I hiken/ar: WRLTE'R LIMBERGER w. LIMBERGER 3,516,344 SILVER SALT DIFFUSION APPAR TUS FOR CARRYING OUT THE TRANSFER PROCESS Filed Nov. 22, 1966 JuIIC 23, 1970 '7 Sheets-Sheet '7 lnven/ar: WRLTER LIMBERGER B7 W ATMRueys United States Patent 3,516,344 SILVER SALT DIFFUSION APPARATUS FOR CARRYING OUT THE TRANSFER PROCESS Walter Limberger, Hamburg-Poppenbntte], Germany, assignor to Lumoprint Zindler KG, Hamburg, Germany Filed Nov. 22, 1966, Ser. No. 596,221 Claims priority, applicatign 2Gzelrmany, Nov. 25, 1965, Int. Cl. G03d 9/00 U.S. CI. 95-89 17 Claims ABSTRACT OF THE DISCLOSURE Silver salt diffusion transfer method in which the receiving material prior to contact with the negative material is moistened with a liquid and squeezed. A second squeezing takes place while the receiving material and the negative are in contact with each other.

Apparatus for carrying out the procedure is also disclosed.

The invention relates to a silver salt diffusion transfer apparatus using a negative material, on the silver halide emulsion layer of which an image is formed by exposure, and a receptor or receiving material, to which the image is transferred, wherein the exposed negative material is moistened with a liquid for effecting development and is subjected to compression in contact with the moistened receptor material of paper, film or textile material.

In German specification No. 764,572, the so-called silver salt diffusion process is described and it is stated that various materials are used as the receptor image carrier, for example uncoated papers, textiles, wood, celluloid and other synthetic materials and the like. -It may be mentioned that the expression material as used herein means any material of sheet form.

The aforementioned specification states that the transfer can be assisted by the presence of materials which favour diffusion. The diffusing or diffused silver halide can be developed imagewise without exposure, this development being assisted by added nuclei or reactants. The developed image is applied for instance to a barytapaper or a textile support which has been moistened 1n the same bath as the silver halide material.

In carrying out the process in practice as it has been developed for commercial use employing sheet-like copy materials, a separate positive or receptor layer has been provided, in which the reduction nuclei are contained. This layer is generally provided on a special support, so that the layer and the support form the receptor material.

It is also known to use the receptor layer independently of a support and apply it for instance as a cover layer or overcoating on the negative layer. Such a system is described in specification No. 1,171,740 and uses colloidal overcoatings and receptor layers. No reduction nuclei need be contained in this layer. According to specification No. 1,171,740, reduction nuclei are supplied to the colloidal receptor layer by means of the treating liquid. The reduction nuclei can be provided according to the specification mentioned as sulphides, selenides, polysulphides, polyselenides, thiourea, mercaptans, tin halides, heavy metals or their salts as well as fogged silver halides and sulfides of heavy metals such as antimony, bismuth, cadmium, cobalt, lead, nickel and silver. Heavy metals, for instance silver, gold, platinum, palladium and mercury, preferably in colloidal form, are considered the most effective. The noble metals are particularly preferred.

In the method according to specification No. 1,171,740, the image-receiving layer provided in the usual way is thus arranged as an overcoating on the negative and a sheet is provided for receiving the image developed in the over- 3,516,344 Patented June 23, 1970 ice coating. Since according to specification No. 764,572 a difficultly-soluble silver compound or colloidal silver, which is produced in the receptor layer, is to be considered nondiffusible, the colloidal overcoating or image receptor layer containing the reveloped image is during transfer thus also transferred to the receptor sheet paper or the like.

In other copying methods, it is, already possible to transfer a usable image to a normal paper sheet without using a positive layer. This applies, however, to physical methods, such as the electrophotographic method for instance.

German specification Nos. 764,572, and 1,171,740 are based on the use of reduction nuclei, as they have already been used in practice in the silver salt diffusion process known as the Copyrapid method.

If the reduction nuclei, according to specification No. 1,171,740, are provided in the treating liquid which not only serves to carry out development, but also for the formation of complex salts of the unexposed and undeveloped silver halide, the same limitations arise with regard to the stability of such solutions as are known to exist with developers used in the silver salt diffusion process. These limitations are due to the simultaneous presence of atmospheric oxidation products and used and unused developer substances, the increasing content of silver halide solvents caused by the increasing number of copies and silver halide complex compounds which diffuse into the solution and may be active as reduction nuclei.

The invention has as its task to provide a process which allows the economic formation of a positive image on an uncoated support by means of the silver salt diffusion process, wherein the liquids used have satisfactory stability and productiveness.

The expression uncoated support means a sheet, e.g. of paper, which contains no film-forming colloids, but for which only a moistening with an aqueous solution is to be provided.

A further object of the invention is to enable the use of simple and inexpensive materials.

A further object of the invention is to provide a process and an apparatus wherein, for carrying out the transfer process, one of the materials can be used uncoated, so that the problem of providing multiple coatings on a support are avoided. With the production of multiple coatings, the possibility arises, probably with long storage and/or through changing effects of atmospheric moisture and temperature, that damage can occur, especially if special binding agents are not provided.

In contrast to known methods, it is novel to moisten the receptor material with another liquid before associating it with the negative material, which other liquid contains reduction nuclei or substances forming reduction nuclei and a silver salt solvent in aqueous solution. Such procedure has the advantage of operating without a filmforming colloid receptor layer and normal diffusion negative material is usable. Further advantages reside in the composition of the liquids used due to their stability and to the possibility of making a larger number of copies. It has surprisingly been shown that, for example, using the so-called Copyrapid dry negative material, a trade name of Agfa Gevaert A.G., or the so-called Kodak dry paper which are commercially available, substantially better results can be obtained with the method according to the invention. Such use is therefore a further embodiment of the invention. Separate moistening of the receptor material and of the negative material with different liquids, thus saving a receptor layer in the actual sense per se, leads to satisfactory copies if the two materials are brought together in the moist state and subjected to pressure.

The moistening does not extend to a so-called coating. Such an operation is known for example from German specification No. 1,168,927. This relates to a coating process on uncoated paper for carrying out a heat copy method, which provides that the original is subjected to infra-red radiation in surface-to-surface contact with the coated support. It is therefore necessary to dry the coating solution before bringing it together with the original, in order not to damage the original.

In this known method, no diffusion or transfer process is involved, but a definite coloration at a predetermined temperature corresponding to the selective heating caused by the radiant energy absorbed by the dark characters of the original.

In contrast and according to the invention, a receptor material is used which, after moistening, is subjected to wiping or squeezing at least on the moistened side and is brought into contact with the negative material. This wiping or squeezing apparently not only has the effect of removing the liquid, but liquid is also forced with a uniform distribution, at least into the moistened surface, whereby no liquid film remains on the surface and therefore the formation or precipitation of silver halide complex salt diffusing from the negative does not take place in the liquid film, but on the paper surface. Surface precipitation of the diffusing salt onto the surface likewise is favoured by the fact that the reduction nuclei are present in the dissolved state in the receptor sheet. If instead of direct moistening and wiping or squeezing, factory preparation and drying of the receptor material would be provided for, a loss in quality of about 50% would occur as regards darkening of the silver image, since the nuclei would be uniformly distributed in the material and a silver salt precipitate picture of the diffusing complex salt would be formed which penetrates the depth of the paper thickness.

The invention therefore provides that the receptor material is subjugated to two separate squeezing operations, the first of which takes place before bringing it into contact with the negative material and the other after bringing it into contact and while still in contact with the negative material.

The invention is based, on the one hand, on separate moistening of the two materials, a procedure which is by no means obvious and itself leads to significant advantages and, on the other hand, on the use of a material, namely the receptor material, which is subjected to a treatment which leads to a surprising result. This treatment is a combination of the application of the chemical liquid and a mechanical action, which in cooperation considerably improve the result.

Where reference is made to moistening, it is also possible to moisten merely one side of the sheet receptor material, namely that side on which the image is formed.

Moistening can be carried out in any suitable way, such as spraying, application by means of a moistening roller or the like. Advantageously, the receptor material is advanced in known manner through the liquid and is sub jected to roller squeezing before contacting the negative material. Roller squeezing has the advantage that, apart from the above-described effect, excess liquid is removed. Double squeezing of the receptor material leads to drier copies than previously possible and the undesirable roller effect on the copies is safely avoided.

According to a particularly preferred embodiment, commercial Copyrapid dry negative paper or Kodak dry paper is used as the negative material and an activator provided for these materials is used as the developer liquid. In using normal silver salt diffusion negative papers, a developer commercially available for such papers is also used.

To improve the economics of the method, an important feature consists in using, as the treating liquid for the receptor material, a solution with a concentration of about 0.02% hexachloroplatinic (1V) acid and/or gold (III) chloride hydrochloric acid. It has been ascertained that, for the reasons mentioned above, by using such a liquid substantially more copies can be made than if the nuclei are contained in the developer liquid itself.

. Where reference is made to reduction nuclei, there is the possibility, if required, of using a combination of such nuclei.

The present invention is characterised in that not only are the treatment baths simple, stable and relatively inexpensive, but thy lead to a commercially utilisable method in which ordinary papers can be used, without additional coatings on the negative materials having to be provided.

If additional coatings were provided, the advantages of being able to use a simple paper sheet as the receptor material would be substantia ly lost by the more complicated construction of the negative.

It has also been found that it is not possible, using the features described, to use ordinary prepared papers which are produced by immersion with an aqueous solution, of a composition necessary for treating the receptor material and subsequent drying. Such a procedure does not lead to the desired result. The invention therefore provides in its simplest form not only a new method in which the time for the occurrence of the chemical and physical phenomena is chosen at will, but it also depends on a predetermined timely sequence of operational steps independent of in which the receptor material must be moistened with a certain liquid immediately before contacting the transfer material.

The terms used in the following examples for the liquid have the following meaning:

H O=Dist. water Mirasol=0.5 soln. in H O (wetting agent) Na S O -so1n.=Sodinm thiosulphate 1% in H O AgNO -soln.:1% silver nitrate soln. in H O Gold-soln.=1% gold (III) chloride hydrochloride acid,

yellow in H O, H(AuCl -4H O Platinum-soln.: 1 hexachloroplatinic (IV) acid, dry in EX. I:

1000 ml. H 0

15 ml. Mirasol 20 ml. Ag NO -soln.

40 ml. Na S O -soln. Ex. II:

1000 ml. H 0

15 ml. Mirasol 20 ml. gold-soln.

10 ml. Na S O -soln. Ex. III:

1000 ml. H 0

15 ml. Mirasol 5 ml. gold-soln.

1 ml. Na s O -soln. Ex. IV:

1000 ml. H 0

15 ml. Mirasol 10 ml. platinum-soln.

5 ml. Na S O -soln.

5 ml. gold-soln. EX. V:

1000 ml. H 0

15 ml. Mirasol 10 ml. platinum-soln.

5 ml. Na S O -soln.

10 ml. gold-soln.

To carry out the method, the invention provides an apparatus using two liquid baths through which the transfer material and receptor material are advanced before they are guided to a common pair of squeezing rollers.

An apparatus is known, for example, which is constructed in the form of shell members and two conformed curved channels for sheet materials are included, the base of one channel forming the cover of the channel located therebelow and the two channels being filled with different liquids. At the end of the two channe s, a common pair of squeezing and advancing rollers are provided 'for the materials emerging from the different channels. Also, surface-moistening devices are known, in which two separate baths are provided whose containers are superposed. Above the edge is located a pair of squeezing and advancing rollers, which are common to both sheets of material, one of which is guided over a bath to be moistened on one side. The invention extends to surface moistening and also to moistening by means of advance through the liquid. The two methods can be combined, one copy sheet being advanced through the liquid and the other copy sheet being subjected to uni lateral moistening on a liquid meniscus by contact therewith. Surface moistening is also possible by spraying or roller application. In any case, by the two baths, one of which can if required have separate applicator means, two guide paths are provided through which each of the copy materials is guided, whereupon both copy materials are guided to the common pair of squeezing and advancing rollers.

The apparatus according to the invention is distinguished from this in that a second pair of squeezing rollers is arranged in the guide path for one copy sheet between the common pair of squeezing rollers and the treating bath. This device provides the especially advantageous method, with preliminary squeezing before contact with the negative material.

In an embodiment in which the two treatment baths are provided one above the other and the curved base of one treatment bath covers the top of the other treatment bath, a preferred embodiment of the invention consists in that guide elements of both treatment baths define guide paths to a pair of squeezing and advancing rollers and additional guide means are arranged between the two pairs of squeezing and advancing rollers, which lead the sheet guided through a second pair of rollers to the common pair of squeezing and advancing rollers.

Advantageously between the pairs of squeezing and advancing rollers, an arrangement is provided which causes downward deflection of the receptor sheet before its entry into the common pair of rollers, in order to cause drainage of liquid above receiver or catching elements. According to a particularly preferred embodiment, this arrangement is developed so that the previous pair of squeezing and advancing rollers are driven somewhat more rapidly than the later pair of such rollers. By this, a bending of the copy sheet is obtained "for the purpose of guiding it in an S-shaped curve without using additional mechanical guide elements.

'It will be understood that in an embodiment of the invention the common pair of squeezing and advancing rollers is arranged inclined to the second pair of such rollers relative to the imaginary line interconnecting the axes of the rollers, so that the sheet passing through is directed round and towards the subsequent pair of squeezing and advancing rollers. By this arrangement, with different driving velocities, the solution already mentioned can be obtained. Further preferably the preceding pair of rollers is arrangd at the outlet from the upper treating bath and guide means can be formed on one side from the extended base of the upper treatment bath. The construction so achived is particularly economical.

According to a further feature of the invention, the common pair of squeezing and advancing rollers is arranged above the bath of the developer liquid, for the purpose of returning the liquid falling ofi, whereas the pair of squeezing and advancing rollers for the liquid for the negative material are located on the vertical projection of the common pair of rollers and/or beneath the base for the liquid bath for the developer liquid. In this way, guide ribs can be advantageously arranged between the two pairs of squeezing and advancing rollers with an arrow-like profiling, which ensures that developer liquid falling off is guided downwardly on these ribs and does not run along the ribs. It will be understood that a separate receiver is provided in order to receive this liquid.

According to an advantageous embodiment of the invention, the second pair of squeezing and advancing rollers and the common pair of squeezing and advancing rollers are so arranged that the zones of contact are provided at substantially the same level, the pairs of squeezing and transport rollers being provided with substantially vertically superposed rollers. This has the advantage that the so-called positive runs substantially horizontal between the pairs of rollers, so that adhering liquid cannot flow back and come into contact withthe negative material. In a more advantageous way, the preceding pair of rollers consists of rollers with a smaller diameter than the common pair of rollers and the drive is so arranged that the peripheral velocity of both pairs of rollers is the same. This gives improvements as regards squeezing off of the liquid and smooth advance of the receptor material.

According to a further embodiment of the invention, the second pair of squeezing and advancing rollers are advantageously arranged so that the imaginary line interconnecting their roller axes runs horizontally and is provided above the contact zone with a guide element between the rollers, which leads to the higher located and later disposed pair of squeezing and advancing rollers.

According to another feature, the second pair of rollers is provided behind the lower treating bath and approximately at the same level as the subsequent pair of rollers.

If the second pair of rollers is located behind the lower treating bath, a further advantageous embodiment is given in which the imaginary line interconnecting the roller axes is arranged substantially horizontally, whereas the common pair of squeezing and transport rollers is so arranged that the imaginary line interconnecting their roller axes is inclined to the horizontal and is directed forwardly with the upper end from the on-running side, so that the base and/or guide means for the upper treating bath are curved through Before the preferred embodiments of the method are described, a basically very simple method will be given. According to this method, an image-wise exposed commercial negative is moistened with the commercial developer therefor and is laid on a flat surface with the layer uppermost. Thereafter an ordinary sheet of paper is moistened with an aqueous solution of so-called reduction nuclei and a silver salt solvent and the moistened paper is then rolled by means of a roller squeezer. Thereafter the moistened side of the paper, if only one side is moistened, is laid on the negative and the two are pressed together with a roller. After a transfer time, which is known in practical silver salt diffusion methods, the two sheets are separated and an image of the original appears on the ordinary paper.

As the paper for a particularly advantageous form of the method, so-called raw paper is used, for example of that quality containing 70 to 90 g. or thereover of the firm of Schoeller.

In order that the invention may be readily understood, preferred embodiments thereof are described below in conjunction with the accompanying drawings. In the drawings:

FIG. 1 shows a side view of a developer insert section in cross-section;

FIG. 2 shows a cross-section on the line IIII of FIG. 1;

FIG. 3 shows a diagrammatic side view of another embodiment;

FIG. 3a shows a partial view in plan of a portion of FIG. 3 corresponding to line III-III;

FIG. 4 shows a side view of a developer unit in crosssection and diagrammatic representation;

FIG. 5 shows a side view of an apparatus with another form of developer unit in cross-section;

FIG. 6 shows a cross-section on the line VI--VI of FIG.

FIG. 7 shows a side view of a developer unit in crosssection.

Although only developer units are shown in some of the accompanying figures, it should be understood that the arrangement of such developer units in apparatus is included, which also involve developing devices, storage arrangements for liquids and the like. The method according to the invention is practised within the kind of apparatus known as the developer unit type, so that sufiicient description of this is given to explain the invention. A basic arrangement for a form of apparatus is shown in FIG. 5.

The examples relate to a so-called interrelated or closecoupled developer unit, in which the guide paths for the various materials lie one above the other. It has also already been mentioned that other arrangements are possible, particularly for the use of surface moistening. Where, in the following examples, advance through a liquid is described, it can be taken that this includes the case where a liquid bath can be replaced in the apparatus by roller arrangement, the rollers of which serve as guide elements in the guide path and act to apply liquid to the advancing sheet of material.

In FIG. 1, a developer unit includes a lower shell member 1 and an upper shell member 2, which runs at least partially in substantial conformity to the lower shell member, the two shell members being separated from one another in separate spaces. This can be arranged by securing both shell members as bases between common side walls, as can be seen in FIG. 2, or by internesting both shell members with their own side walls, the required distance and direction being obtained by guide projections.

The shell members also form guide means for the sheets passing through. In order to minimise rubbing, rib-like guide webs 3, 4, 5 and 6 are arranged in the longitudinal direction of the shell members, which webs ensure, particularly in relation to the shell member 2, the lower side of the sheet advancing through is moistened with liquid. The guide webs can run at an angle to the direction of the advance, which ensures that all portions of the surfaces are moistened.

The upper or inner shell member 2 is provided with a guide element 7, which extends from the front edge of the shell member 2 or the inlet end at least into the liquid, and advantageously is curved in arcuate form and is guided more or less to or over the lower curved point of the shell member 2. This guide element 7 can be made wavy in cross-section for reinforcement purposes. It serves to ensure immersion of the sheet into the liquid.

The lower shell member 1 extends to an upwardly curved portion 8 on which, within the shell for example mounted in the side walls thereof, a pair of squeezing and advancing rollers consisting of rollers 9 and 10 is arranged. These rollers are drivable in the direction of the arrows shown. The drive can be provided, in the most simple form, by hand. Advantageously, a motorised drive is provided, by way of a transmission gear which is connected to the main driving motor of an apparatus.

In the side walls either of the outer shell member 1 or of the inner shell member 2, a second pair of squeezing and advancing rollers 11, 12 is arranged, which are driven in corresponding manner in the direction of the arrows shown. It can be seen that the guide elements 6 on the second shell member 2 have an increased projection 13 which leads to the nip or contact zone between the rollers 11, 12, in order to guide an advancing sheet to that contact zone and thus through the contacted rollers 11, 12. The second shell member 2 has a cover 14 which includes strip-like guide elements 15 on its lower side. Adjacent the rollers 11, 12, these elements Cir 15 have a downwardly-directed projection 16, the tip of which in the embodiment shown lies somewhat to the left of the tangent at the contact position. The guide elements 15 have an upwardly-curved shape and a prolongation 17, which extends downwardly as a projection and leads in arcuate form to the contact zone between the rollers 9, 10.

The guide webs 4 are raised so far from the shell member 1 at 18 that they lead to the contact zone between the rollers 9, 10. The underside of the shell member 2, which can have a bend 19 to surround the pair of rollers 11, 12, is likewise provided with guide webs which extend at 20 behind the shell member so that a sheet which is guided by the shell member 1 is guided towards the contact zone between the rollers 9, 10.

It may also be mentioned that, in the present example, the pair of rollers 9, 10 on the one hand and 11, 12 on the other are staggered with respect to one another in vertical projection. Liquid removed by means of the rollers 11, 12 thus passes into the bath 21 on the shell member 2, whereas liquid squeezed out between the rollers 9, 10 returns to the bath 22 on the shell member 1. The downwardly-directed curvature of the guide elements 17 has the purpose, through the arcuate guidance of causing liquid from the bath 21 to fall off as much as possible over the shell member 2 or before entry into the pair of rollers 9, 10. In any case, it is essential that no liquid from the bath 22 passes into the bath 21, whereas a certain transfer from the bath 21 to the bath 22 is not harmful. In the bath 21, the treating liquid already described for the receptor material is provided, whereas the bath 22 contains the developer liquid for the negative material.

The axes of the rollers 11, 12, 9 and 10 shown diagrammatically and are indicated at 141, 142 and 143. On the spindle 141, a driving motor 144 or a part corresponding to the part 26 of FIG. 2 is provided. The spindles 140 to 143 are connected together by transmission means 145, 146, 147. The arrangement is provided in a frame which has at least the side walls 23, 24 shown in FIG. 2, the lower portions of which are indicated in general at 148 and include the space 25 defined for the drive means by the side wall 149. It will be understood that at least the side walls 23, 24 are raised corresponding to the cross-section in FIG. 1 in order to receive the pair of rollers 8, 9.

It can be seen from FIG. 2 that, for example the shell member 1 is connected with the side walls 23, 24, between which the shell member 2 is arranged, and in which the pairs of transport rollers are mounted, the roller 12 being shown. In an adjacent space 25, the transmission and driving unit 26 is located.

It can also be seen that the guide elements 4, 13, 15, 20 are constructed in strip form or web form. The construction of apparatus shown facilitates manufacture of a developer device.

FIG. 3 shows an arrangement constructed on an ordinary basis. The lower shell member 27 with web-like guide elements leads to the common pair of squeezing and advancing rollers 28, 29 which are driven for example by a driving motor 30. The upper shell member 31 with corresponding guide elements leads towards the pair of rollers 32, 33, which are driven for example by the driving motor 34. It can be seen that the guide elements 35, 36 arranged on the shell members with raised portions lead the material passing to the contact Zone of the pairs of squeezing and advancing rollers. The cover 37 of the upper shell member 31 has downwardly-projecting web-like guide elements 38, which impose an arcuate guide path through the bath in the upper shell member 31 towards the pair of rollers 32, 33. The driven squeezing and advancing rollers 33, 29 frictionally drive the associated squeezing and advancing rollers 32, 29, if required through the intermediary of a copy sheet. Transmission means can be arranged between these various spindles, as shown in FIG. 1 by references 145 and 147.

This arrangement is also provided like all the other features in a frame, which is generally indicated in FIG. 3 at 151 and includes supporting side walls, of which for example a portion 152 is raised upwardly for providing on the side walls support for the pairs of squeezing and advancing rollers above the bath containers.

The imaginary line interconnecting the axes of rollers 32, 33 is inclined so that a copy sheet passing through is guided to the roller 28 of the pair of rollers 28, 29.

The leading edge of the copy sheet is then taken by the roller 28 to the nip between the rollers 28, 29. Because of the direction of the connecting line mentioned, the copy sheet impinges on the roller 28 at a position which approximately corresponds to the 8 oclock position in the associated circle. On further advance, this copy sheet, the course of which is indicated in dotted lines at 39, is taken around the lower periphery of the roller 28, so that an upwardly-directed curve in the .guidance of this material takes place. The downwardlydirected curve ensures that drainage takes place at the lowermost turning point. This drainage prevents excess liquid from being carried onto the pair of rollers 28, 29 and particularly that the major part of the draining liquid passes into the bath on the shell member 31.

For this purpose, the end of the shell member 31 is raised at 40 and provided with web-like guide means 41 which ensure passage of the sheet towards the roller 28. At the end 40, largely upright webs 42 are provided for guiding the copy sheet into the pair of rollers 28, 29 which are shown in plan view in FIG. 341. These webs are provided on both sides with saw-tooth portions 43, 44. These saw-tooth portions prevent liquid squeezed out in the pair of rollers 28, 29 from passing into the bath on the shell member 31. Such liquid drops instead into the bath on the shell member 27. It is essential that the drive means 34 serve to drive the pair of rollers 32, 33 with a somewhat higher velocity than the drive means 30 for the pair of rollers 28, 29. In the passage of the copy material, the upwardly directed path thus ensures, as indicated at 39, that excess liquid drains oil properly.

Whereas FIGS. 1 to 3 show one solution, in which the liquid bath for the receptor material is upwardly open and in which additional pairs of rollers 11, 12, 32, 33 are arranged to the left of the common pair of squeezing and advancing rollers 9, 10, 28, 29, FIGS. 4 and show solutions in which the liquid bath for the receptor material is provided below.

The lower shell member 45 has strip-like guide elements 46 which lead by way of a curved section 47 to a driven pair of squeezing and advancing rollers 48, 49. The upper shell member 50 has guide elements 51 at its underside, which likewise ensure that the advancing copy sheet passes to the rollers 48, 49. The liquid meniscus is indicated at 52. The upper shell member 50 has strip-like guide elements 53 on its upper side, which lead to the end 54 of the upper shell member. The upper shell member is curved upwardly and the curvature is so arranged that a tendency for return of the copy sheet occurs.

correspondingly, the common pair of squeezing and advancing rollers 55, 56 are provided in an arrangement such that the advancing copy sheets pass to the entry side at 57, where the arrows 58, 59 indicate the inserted copy sheets. The curvature of the upper shell member 50 toward the common pair of squeezing and advancing rollers 55, 56 has the purpose, in the region of this pair of rollers, of allowing liquid squeezed off not to return to the bath on the shell member 45. For this reason, an essential feature is that the common pair of rollers 55, 56 are located above a developer bath, whose liquid meniscus is indicated at 60 and which serves for developing the negative layer support, so that in no case draining liquid can pass into the liquid bath above the shell member 45 for the receptor layer support.

The upper shell member 50 is covered with a lid member 61, which has strip-shaped guide elements 62 on its lower side, which define the course of the copy material corresponding to the shell member 50.

Between the pair-s of rollers 48, 49 and 55, 56, a connecting guide element '63 with guide webs 64 is provided. This guide element is so arranged that the receptor material, which is guided through the pair of squeezing and advancing rollers 48, 49, is directed towards the common pair of rollers 55, 56. The pair of rollers 48, 49 are arranged together at such an inclined position that the material passing through has a tendency to undergo a curved movement. For liquid falling off at the guide elements 63, 64, a receiver 65 is arranged on the upper shell member 50 which, if required, can have a connecting opening to the bath on the shell member 45.

The bearings for the rollers are not shown. They are arranged in side walls of the apparatus.

An arrangement corresponding to that in FIG. 2 is suitable. The rear side wall, at least of the bath insert, is indicated at 143. This side wall end-s at the entry side along the lines 154, 155. In the region of the portion 153, the pairs of rollers 48, 49 and 65, 66 are mounted in the manner shown in FIG. 2. and are driven in the direction of the arrows shown. Behind the side wall portion 153 in the manner already mentioned, such as shown diagrammatically in FIG. 4, driving means 156 and 157 are provided which are arranged for example on the spindles of the rollers 49, 56 and are connectible, on the provision of electric motors, to a source of potential, like the previously-described motors 144, 26, 30 and 34.

The embodiment according to FIG. 4 has different lengths of paths of travel for the different copy sheets. For this reason, the receivers 66, 67 of the shell members are displaced in staggered fashion, so that the receptor material is brought into position corresponding to the arrow 59 so that both copy sheets pass together int-o the pair of rollers 55, 56.

FIG. 5 shows a special device, of which the developer insert is first described below. This consists of the lower shell member 68 for the receptor sheet and the upper shell member 69 for the negative layer support which has been exposed. The baths are shown at 70, 71. Whereas the upper shell member 69 has guide elements 72, which ensure the passage of the receptor sheet through the lower bath, an additional guide element 73 is arranged above the upper shell member 69 and corresponds to the guide element 7 of FIG. 1.

The shell member 68 extends a certain distance towards the right as an intermediate wall 74 of the apparatus, in the horizontal direction, as seen from the bath in FIG. 5. Above this horizontal intermediate wall, two chambers are formed by wall portions 75, 76 extending vertically to the plane of the drawing. In the chamber located to the left of the wall 75, at least one roller of the pair of squeezing and advancing rollers 77, 78 is located, which is driven in the direction of the arrows shown. Liquid squeezed out in this pair of rollers thus passes into the bath on the shell member 68. On the horizontal wall, web-like guide projections 79 are arranged and ensure that the copy sheet passes to the nip zone between the rollers 77, 78.

The upper shell member 69 is curved at 80 over the upper roller 78 and is then guided downwardly with an end section 81. On this, web-like guide elements 82 are located which run substantially in the direction of advance and extend over the wall 65. Thus copy material coming through the rollers 77, 78 is guided on the guide elements 82 to a common pair of squeezing and advancing rollers 83, 84 their axes being provided in vertical superposition and the lower axis being located in the chamber formed between the walls 75, 76.

A cover member 85 for the upper bath carries guide elements 86, which can be made in web form or from wires, and are curved upwardly at 80 corresponding to the 'cluded.

In order to ensure a change of direction at 87, the possibility is given of providing a socalled disc roller 89, which, can be driven or freely rotatable and is arranged a certain distance above guide elements 90 on the upper shell, member 69 and has the purpose of directing copy ma-,

terial running on the shell member 69, as free as possible from friction, into the domed part 80 of the upper shell member. I

The apparatus according to FIG. 5 also has an inlet opening 91 for the copy material sheets, the negative material of which has been exposed, and an outlet opening 92. Moreover, behind an opening 93 beneath the outlet opening 92, a known illuminating device is arranged. This consists of three guide rollers 94, 95, 96, one of which at least is driven, and round which single or multiple bands 97 are trained, in which a cylinder 98 of translucent material is held guided between the rollers 94, 96. The cylinder 98, of glass for instance, has a greater diameter than the distance between the rollers 94, 96. An exposure light source 99 is mounted within the cylinder.

Nearby the illuminating device and beneath the developer bath, two supply containers 100, 101 consisting in known manner of elastic material are arranged under a compression plate 102. The latter is downwardly movable by means of a lever 103, so that there is a predetermined spring effect which is described further below. From each plastic bottle 100, 101, a connecting pipe 104, 105 leads to each of the baths 70, 71 so that these baths are replen ished on movement of the plate 102 or return from the baths to the storage containers can be effected.

The pipe connections 104, 105 discharge into connec- 'tion members 167, 168, which discharge thereinto at the lowest parts of the relevant baths.

In FIG. 6, the same parts are indicated with the same 'references. It can be seen that the baths, shown generally at 106, are arranged to the left at the top. The so-called insert can be supported upon an intermediate wall 107. Upon the side wall 108 of the bath running inwardly of the device, through which pass the driving shafts of the pairs of squeezing and advancing rollers, transmission members 109 engage which are driven from a central driving motor 110. The transmission 109 is constructed for example correspondingly to the transmissions 145, 146 and 147 of FIG. 1, wherein additional transmissions are provided for driving at least one of the rollers 94 to 96 of the illumination device.

The rotating parts are mounted corresponding to the, arrangement according to FIG. 2 in an apparatus in side or support walls running parallel to the plane of the drawing. One of these side walls is shown in FIGS. 5 and 6 at 112. It can also be seen that this wall, at the same time,

forms a side wall of the bath container arrangement whose other side wall is shown in FIG. 6 at 159. This is secured to the intermediate wall 74 or on the shell member 68 and extends for example beneath a cover member.

160 located in the inlet opening 190. The other openings passing to the rollers 83 and 95, if required, corresponding to the line 165 and also to the roller 89 as shown in FIG. 5. A driving motor is indicated by the dotted circle 166 and corresponds to the driving motor in FIG. '6. It can also be seen that the two storage containers 100, 101 are located beneath the plate 102. Also it can be seen that the lever 103 which is mounted at a pivot 111 is rotatably coupled with a shaft 113 passing through the side wall 112, on which shaft a crank '114 with a handle 115 is located. This crank is itself located in a housing extension 116. The housing has, for example, an arcuate outlet slot 117 through which the handle 115 projects. A spring 118 is secured to the crank arm, whose other end is secured to a support member 119. For example, the crank 114 and the spring 118 are shown in dotted lines in FIG. 5. It can also be seen that counterclockwise movement of the crank from the position 114 in FIG. 5 leads to a deadpoint at the position 114 of the spring 118, so that a stable support in either position is attained.

It is merely essential for the invention that two supply containers 100, 101 be arranged and that the two hose connections 104, 105 are provided for connection with the separate baths, so that a separate storage of the baths is thus provided.

In FIG. 7, a further embodiment of the developing insert is shown. This consists of two shell members 120, 121, the latter of which forms the upper bath 122 and the former forms the lower bath 123. Both shell mem-- bers 120, 121 are mounted on chamberlike inserts with substantially horizontal base sections 124, 125 and up right end Wall sections 126, 127. In these shell members run the lower rollers 128, 129 of the superposed and common transport and squeeze rollers, the other rollers of which are indicated at 130 and 131.

The shell members are provided with web-like guide elements 132, 133 which rise up in front of the rollers by means of sections 134, 135, which direct the moving material into the roller gaps.

For example, for the common pair of squeezing and advancing rollers, a group of substantially triangular fiat guide elements 136 is arranged on the upright end wall 126.

The spindle of the roller 128 passes through the side walls of the shell member 121 (not otherwise shown), if required using glands or other sealing means. A side wall part, which can be equivalent to the side walls of the developer shell, is shown at 137 and forms a support wall on which the rollers are mounted. At the rear of the support wall, at least one driving motor is arranged, which is shown diagrammatically on the spindle 166 and the roller 131 and 167. Also a transmission 168 connected to the spindle 169 of the roller 130 is shown dia grammatically.

It will be understood that such an insert can be ar ranged in an apparatus according to FIGS. 5 and 6 and that a supply arrangement with containers 100 and 101 and pipe connections 104, 105 can also be provided. 'Otherwise, the rollers are mounted in support walls 137, on which driving means can be arranged in the ways already described. It is important that the contact zones between the pairs of rollers 12 8, 130 and 129, 137 lie at such a level that the copy material which is advanced between the rollers runs horizontally and any return of liquid into the bath 122 is avoided. The driving means are so arranged or have such a transmission ratio be tween the two pairs of rollers that the same peripheral velocities apply. It can also be seen that liquid draining off from the common pair of rollers can return to the bath 123.

cable drives corresponding to the dotted lines 158, 164 and 75 The smaller radius of curvature of the pair of rollers 128, 130 leads to better squeezing conditions and prevents any adhesion of the pair of rollers.

The arrangement is provided at the top with a cover member 138 which is curved downwardly in the way already described and carries web-like guide elements 139, in order to guide the layer supports through the liquid.

I claim:

1. Apparatus for carrying out a silver salt diffusion transfer process using a negative material, on the silver halide emulsion layer of which an image is formed, and a receptor material, to which the image is transferred, wherein the exposed negative material is moistened with a liquid for effecting development and is subjected to compression in contact with the moistened receptor material which comprises paper, film or textile material, said apparatus comprising a first bath container, first guide means associated with said first bath container, a first supply of liquid in said first bath container for advancing a copy sheet through said first liquid, a second bath container, a second supply of liquid in said second bath container, second guide means for guiding the second copy sheet through said second liquid, a first pair of squeezing and advancing rollers at the outlets from said second and first bath containers for advancing, while under compression, the two copy sheets from the first and second bath containers, a second pair of squeezing and advancing rollers between said first pair of rollers and said first bath container for advancing the copy sheet guided through the first supply of liquid through said second pair of rollers before contacting said second copy sheet, drive means for said first and second pairs of rollers and a frame whereon said parts are mounted.

2. Apparatus according to claim 1, wherein said first and second pairs of rollers are so inter-related that the base of the first bath container forms at least a part of the second guide means for the second bath container, guide elements being provided in each bath container and parts of the first and second guide means being associated with each one of the pairs of squeezing and advancing rollers, which parts surround said first and second pairs of rollers, and wherein additional guide elements are provided adjacent the first guide means which elements extend between said first and second pairs of rollers and serve to guide toward the second pair of rollers a copy sheet which is advanced only through said second pair of rollers, whereby both copy sheets are advanced through said second pair of rollers.

3. Apparatus according to claim 2, wherein said additional guide elements have a profile between said seocnd and first pairs of rollers which causes downward deflection of one of the copy sheets, preferably the receptor sheet, before entry into the first pair of rollers, the contour of additional guide elements located above the path of movement being adapted, before the nip of the first pair of rollers in the direction of advance of the receptor sheet, to include a first downwardly and thereafter an upwardly directed guide portion, the lower crest of said guide portion being located before said roller nip, to cause liquid to drip downwardly therefrom.

4. Apparatus according to claim 3, wherein the additional guide elements are curved in substantially S-shaped form.

5. Apparatus according to claim- 3, wherein said first pair of rollers have a higher peripheral velocity by being driven by an associated drive means than the second pair of rollers by the drive means associated therewith, whereby over the length of the movement of a copy sheet an increasing downwardly-directed bending is given before entry into the first roller pair nip, which bending imposes an S-shaped curved path upon the copy sheet.

6. Apparatus according to claim 2, wherein the first pair of rollers are disposed in a frame which also receives said first and second bath containers and the second bath container has an extension at its outgoing edge which extends to the vicinity of, but stops short of, the vertical projection of the first pair of rollers.

7. Apparatus according to claim 6, wherein guide means are provided which are disposed in the prolongation of the second bath container and extend between said second and first pairs of rollers and are provided with an arrow-like profiling for causing falling developer liquid at the rib-portions of said profiling to pass downwardly.

8. Apparatus according to claim 2, wherein first support means for the first pair of rollers are disposed in a frame also containing second support means for the second pair of rollers so that a line interconnecting the first and second pairs of rollers is inclined, whereby a copy sheet being advanced in the second pair of rollers is deflected round and changed in direction toward the laterdisposed first pair of rollers.

9. Apparatus according to claim 2, wherein the first pair of rollers is provided at the outlet from the first bath container, which is disposed in the frame above the sec ond bath container, said additional guide elements being formed at one side from the extended base of the first upper treatment bath, the second pair of rollers being located in line with said additional guide elements.

10. Apparatus according to claim 9, wherein said second pair of rollers are so mounted in the frame that a line interconnecting the roller axes is horizontal, a guide means being provided over the zone of contact between the rollers of the second pair of rollers directed towards the higher and later located first pair of rollers.

11. Apparatus according to claim 1, wherein the second pair of rollers is arranged, in the direction of advanced of the copy sheets, behind the lower first treatment bath in the frame and the later located first pair of rollers are mounted in the frame substantially at the same level.

12. Apparatus according to claim 1, wherein the first treatment bath is arranged below the second treatment bath and the second pair of rollers are disposed in the frame, relative to the direction of advance of the copy sheets, after the lower first treatment bath, a line interconnecting the roller axes of the second pair of rollers being substantially horizontal, the first pair of rollers being mounted in the frame and arranged so that the line interconnecting their roller axes is inclined to the horizontal and is directed with the upper end forward from the inlet side, the base and the second guide means for the upper treatment bath being curved through about 13. Apparatus for carrying out a transfer process using a negative material, in the silver halide emulsion layer of which an image is formed, and a receptor material, to which the image is transferred, wherein the exposed negative material is moistened with a liquid for effecting development and is brought into contact with the moistened receptor material and wherein the materials are selected from the group consisting of paper, film and textile materials and are subjected to compression together, a first bath container for a copy sheet and first guide means for advancing the first copy sheet through the first bath container being provided, a second bath container being provided and second guide means for advancing the second copy sheet through the second bath containing, wherein a first pair of squeezing and advancing rollers is provided behind a bath container in the direction of advance of copy sheet which is to be selected beneath the bath containers comprising the first and second bath containers, wherein a second pair of squeezing and advancing rollers is provided, behind the first and second bath containers in the direction of advance of both copy sheets, in such a position that the first pair of rollers is disposed between the associated bath container and the second pair of rollers, other guide means being provided between a bath container and the second pair of rollers for bridging the first pair of rollers for the associated copy sheet.

14. Apparatus according to claim 1, wherein a first treatment liquid is provided in the first bath container, a second treatment liquid is provided in the second bath container, a first storage container for the first treatment liquid and a second storage container for the second treatment liquid being provided, a first connecting duct located between the first bath container and the first storage container, a second connecting duct located between the second bath container and the second storage container, pressure means being provided for pressing together the first and second storage containers to supply the first and second treatment liquids to the first and second bath containers, release of the pressure means being adapted to cause return of the first and second treatment liquids to the first and second storage containers.

15. Apparatus according to claim 1, wherein the lower treatment bath contains as the guide means a shell member which is extended as a substantially horizontal intermediate wall whereon vertical wall portions are arranged defining the side walls of a chamber, the first and common pair of rollers being provided in the region of the vertical projection of said chamber and the second pair of rollers being provided on the side of the first intermediate wall located away from the direction of advance of the copy sheets.

16. Apparatus according to claim 2, wherein the second pair of rollers and the first pair of rollers each have a contact zone between the cooperating rollers, both pairs of rollers being mounted in the frame so that the contact zones are substantially at the same level and both consist of two rollers arranged so that the associated rollers are substantially vertically superposed.

17. Apparatus according to claim 16, wherein the second pair of rollers, which are arranged in the frarnebetween a bath container for a copy sheet and the common pair of rollers for both copy sheets, comprise rollers which have smaller diameters than the common pair of rollers, common drive means for the pairs of rollers being provided for driving both pairs of rollers at the same rotational velocity.

References Cited UNITED STATES PATENTS 3,103,153 9/1963 Limberger 95-89 JOHN M. HORAN, Primary Examiner 

